Cultivars of uncertain origin

The hybrid background of the following listed cultivars needs clarification: 'Chocolate Soldier', 'Crimson King', 'Dorothy Walpole', 'Lena', 'Peter Pan' and 'Volcano'.

kingdom Plantae
phylum   Tracheophyta
class    Magnoliopsida
superorder     Rosanae
order      Fabales
family       Fabaceae
genus        Cytisus L.